Usually, each episode would focus on a single investigation. All cases involved murders committed in Philadelphia, although investigations occasionally required travel outside the city. Cases were also spread out over much of the previous century, with some as recent as a year or two old and others dating back to the 1910s. Generally, an investigation would begin when the police received a new lead, or "new direction", on a case. This might be the discovery of a body, a new lead such as an alibi witness not found in the original investigation, new evidence pointing to the innocence of the accused, or a critical piece of evidence such as a murder weapon (e.g., one investigation began when a gun received in a gun buyback program was linked to a murder through ballistic evidence). In some cases, the lack of a body meant that it was originally unclear if a crime had even occurred, with people instead believing that the victim had merely left town.

Over the course of the episode, the detectives would interview witnesses associated with the crime and piece together the story of what led the victims to their death. These interviews were accompanied by flashback sequences to the time of the murder which dramatized the testimony. Witness testimony, even from people who would later be revealed as the killer, was almost never false. At most the guilty party would lie by omission, leaving out critical details, or stopping their narrative before they implicated themselves. The witness testimony was also generally presented in chronological order so that it formed a cohesive linear story for the audience.

The show was also distinguished by "double casting" in which the characters and witnesses would flash back and forth in the scene representing them as they looked at the time of the crime and in the present day. This was done with different actors as children or much younger selves especially if the year in question was well in the past. The oldest case for example took place in 1919. A living witness was seven years old at the time but in 2007 when investigated was now 95. However, if the crime took place in the recent past (i.e. within the last 10 years) the same actor would be used with minor differences, unless it was a child or adolescent. However, if it was judged that the character was not likely to have altered in appearance significantly except for weight and gray hair, the same actor would be used. This was not just with the guest actors themselves but sometimes with the detectives as well if they had any involvement in the original investigation. Detective Jeffries for example had flashbacks to himself as a child in two episodes and a young detective in another.

At the end of the episode, when the killer/s were exposed and confronted the confession would be in a flashback scene depicting the murder. The scene would show the details with exceptions having to do with the utter heinousness of the underlying motive of the crime such as rape or sexual assault. The police would be shown arresting the killer and walking them into custody. The killer and other characters in the story would seen as flashing back to their younger selves and as now. The spirit of the victim would be seen either by Lilly, one of the other detectives or a loved one of the victim. This would be accompanied by the playing of a song meant to symbolize the period in which the killing took place.

Through the flashbacks, the show examined many issues related to 20th century history, including: racism, homophobia, sexism, abortion, and police brutality. Some of the cases were based on real life events or victims, akin to the "ripped from the headlines" style from shows like Law & Order.

CSI: NY crossover

On May 2, 2007, one of the Cold Case detectives made a rare appearance outside of the series. In the CSI: NY episode "Cold Reveal", Danny Pino appeared as his Cold Case character Scotty Valens as he traveled to New York when it was discovered that CSI Stella Bonasera (Melina Kanakaredes) was connected to an unsolved case. The CSI shows and Cold Case all air on CBS and are produced by Jerry Bruckheimer. None of the characters from CSI, however, appeared on Cold Case.

Satire

In 2005, John Finn, Kathryn Morris and Jeremy Ratchford appeared in a satirical promo on the Irish language television station TG4. The commercial won a Gold Medal in the "Best Drama Promos" category of the 2007 Sharks International Advertising Awards Festival of Ireland (Sharks Awards).[5] The promotion features John Finn and Kathryn Morris in character interrogating a murder suspect (Peader Cox) from the TG4 soap Ros na Rún who refuses to speak in English; both detectives then begin talking in Gaelic, much to the surprise of Jeremy Ratchford's character. The promo tied in with a murder investigation in Ros na Rún.[6]

Similar series

The investigation of "cold cases" has been used as the basis for several other detective dramas, including:

Cold Squad controversy

This section is outdated. Please update this article to reflect recent events or newly available information.(September 2015)

After its launch, television critics noted similarities between Cold Case and a similar Canadian series called Cold Squad which debuted five years earlier.[7]Cold Squad fans accused the American series of copying the Canadian program's basic premise and characters. In 2003, the Cold Squad creators considered seeking legal redress against the Cold Case producers over copyright issues.[8][9] Both shows air in Canada (and on the same network, CTV). The law firm headed by entertainment attorney Pierce O'Donnell, who successfully represented Art Buchwald in his copyright-infringement suit against Paramount and who has defended the James Bondfranchise against copycats, confirmed it agreed to represent[clarification needed] the Cold Squad producers, who claim the CBS series is a knock-off of their own hit show. The Globe and Mail reported that Meredith Stehm, the American series creator, attended a TV writing seminar at the Canadian Film Centre in 2002 where the Cold Squad concept was discussed. O'Donnell's law firm commented in a statement: "Our clients are very concerned about many striking similarities and have retained counsel to investigate the situation and, if necessary, to take appropriate action."

In season 3 episode "A Perfect Day" Cold Case set a series rating record by attracting an audience of 19.36 million viewers.

Cancellation

Cold Case began in September 2003 and quickly became a staple of the CBS Sunday night schedule. The crime drama had a successful first season and, by season two, was averaging a 3.5 rating in the 18–49 demographic and 15.1 million viewers. For the next couple seasons, total viewership fell slightly but the demographic numbers rose, reaching a 3.8 in season four.

In season five, the show averaged a 2.9 rating and about 12 million viewers. In Season 6, the ratings sank lower, to an average of a 2.7 rating; CBS made a choice between renewing Without a Trace and Cold Case. They chose to keep Cold Case. In Season 7, the show’s ratings dropped even further to a 2.15 rating in the 18–49 demographic and 9.6 million viewers. One reason for this is that the show aired at 10:00 pm, the ratings dropped 25% to 9 million viewers.[13] On November 22, 2009 CBS scheduled Cold Case at 9:00 pm. The ratings increased to 10 million viewers, but it was not enough to keep Cold Case. On February 14, 2010, Cold Case returned to its original schedule, at 10:00 pm.

Soundtrack

A soundtrack CD was released in 2008 by Lakeshore Records, featuring incidental music composed by Michael A. Levine from the first four seasons, as well as the song 300 Flowers, sung by Robbyn Kirmsse.[14]